The present invention relates to an improved process and apparatus for detecting and removing harmful toxins, such as mycotoxins and benzpyrene (BZP), found in tobacco and tobacco products to ensure that the products are safe for human association and/or consumption. More specificaliy, the invention relates to a novel process and apparatus for continuously detecting, monitoring and removing harmful mycotoxins, in particular, but not limited to, aflatoxins, and benzpyrene and its precursors, during processing of tobacco for human association, consumption and use. Moreover, the novel process and apparatus provide for inhibiting production of harmful toxins in tobacco and tobacco products, and for continuous monitoring and removal of such toxins from solvent and gaseous effluent streams arising from processing tobacco.
Since at least as early as the 1980""s, an increasing concern about public safety has led tobacco processors and refiners to attempt to reduce the tar content of cigarettes. It was this concern about consumer safety that resulted in research in the field of tobacco treatments for manufacturing reformulated tobacco with lower tar. U.S. Pat. No. 4,944,316 to Stuhl et al., entitled xe2x80x9cProcess for Treating Tobacco and Similar Organic Materials.xe2x80x9d
It is believed that safety initiatives by the tobacco companies, however, have only recently addressed some of the most potent carcinogens: mycotoxins. A class of mycotoxins, commonly known as aflatoxins, is one of the most potent carcinogens known to man. Eaton, David L., and John D. Groopman, The Toxicology of Aflatoxins, Academic Press, New York, 1994. Aflatoxins are estimated to be 200 times more carcinogenic than benzpyrene, the most regularly acknowledged carcinogen in tobacco smoke. Moreover, benzpyrene pre-treatment of some species has been associated with an increase in bioactivity of aflatoxins. Ma, Xinfang, Jacqueline A. Gibbons and John C. Babish. xe2x80x9cBenzolelpyrene Pretreatment of Immature, Female C57BL/6J Mice Results in Increased Bioactivation of Aflatoxin B1 in Vitro.xe2x80x9d Toxicology Letters. 1991; 59: 51-58.
Additionally, aflatoxins have been shown to be profound immunosuppressants. Denning, D. W., xe2x80x9cAflatoxin and Outcome from Acute Lower Respiratory Infection in Children in the Philippines.xe2x80x9d Annals of Tropical Paediatrics, 1995; 15: 209-216. A 400% increase in the titers of human immunodeficiency virus (HIV) occurs when exposed to aflatoxin. Yao, Yan, Amy Hoffer, Ching-yi Chang, and Alvaro Puga, xe2x80x9cDioxin Activates HIV-1 Gene Expression by an Oxidative Stress Pathway Requiring a Functional Cytochrome P450 CYP1A1 Enzyme.xe2x80x9d Environmental Health Perspectives, March, 1995; 103: 366-371.
The potency of aflatoxins is further illustrated by its presence as one of the chemical agents in Iraq""s arsenal of chemical weapons. See a study by Anthony H. Cordesman, co-director of the Middle East Program at the Center for Strategic and International Studies, entitled xe2x80x9cWeapons of Mass Destruction in Iraqxe2x80x9d(Nov. 14, 1996).
It has been observed that many tumor types found in experimental animals that are exposed to atlatoxins are the same as the tumor types found in cigarette smokers. As is well known, tobacco use has been associated with an increased incidence of many cancers, typically cancer of the lung, esophagus, mouth, throat, stomach, colon, kidney, bladder, and breast, among others. The presence of mycotoxins, such as aflatoxins, on tobacco may be a cause of the high incidence of cancer associated directly and indirectly with cigarette smoking. Dvorackova, Ivana, M.D. xe2x80x9cAflatoxin Inhalation and Alveolar Cell Carcinoma.xe2x80x9d British Medical Journal, Mar. 20, 1976; 691. El-Maghraby, O. M. and M. A. Abdel-Sater, xe2x80x9cMycoflora and Natural Occurrence of Mycotoxins from Cigarettes id Egypt.xe2x80x9d Zentralblatt fur Mikrobiologie, 1993; 148(4): 253-264.
In addition to danger to a cigarette smoker by the presence of aflatoxins in primary cigarette smoke, aflatoxins may be a special hazard in secondhand smoke. Both aflatoxins, which are dihydrobenzofurofurans, and benzpyrene, are aromatic heterocyclics, which means they are relatively stable. Therefore, although some aflatoxins present in tobacco may be combusted at the combustion temperatures that are produced when a cigarette is burnt by inhaling at one end, aflatoxins have been shown under some smoking conditions, especially idling of a burning cigarette, to survive the combustion process. L. ofroth, Goran and Yngve Zebuhr, xe2x80x9cPolychlorinated Dibenzo-p-dioxins (PCDDs) and Dibenzofurans (PCDFs) in Mainstream and Sidestream Cigarette Smoke.xe2x80x9d Bulletin of Environmental Contamination Toxicology, 1992; 48: 789-794. As secondhand smoke is often combusted at lower temperatures than primary smoke, a larger proportion of aflatoxins may remain undestroyed in secondhand smoke, posing an environmental danger to others. In at least one study, passive or secondary smoke has been linked to repeated occurrences of acute otitis media among pre-school children. Collet. J. P., et al., xe2x80x9cParental Smoking and Risk of Otitis Media in Pre-school Children.xe2x80x9d Canadian Journal of Public Health, July-August, 1995; 86(4): 269-273.
Inhalation of primary or secondhand smoke contaminated with aflatoxios may be inadvertently increasing titers of HIV in individuals thus exposed; for example, pregnant women with HIV, thus increasing the chances of infecting their offspring. Yao, Yan, supra; and Vlahov, David, Ph.D., et al., xe2x80x9cPrognostic Indicators for AIDS and Infectious Disease Death in HIV-Infected Injection Drug Users: Plasma Viral Load and CD4+ Cell Count.xe2x80x9d JAMA, Jan. 7, 1998; 279 (1): 35-40.
These potent health hazards are produced by the Aspergillus and Penicillium fungi, among others, and were known to be present in tobacco and tobacco products since at least the 1960""s. Pattee, Harold E., xe2x80x9cProduction of Aflatoxins by Aspergillus flavus Cultured on Flue-Cured Tobacco.xe2x80x9d Applied Microbiology, November, 1969; 18: 952-953; Welty, R. E., G. B. Lucas, J. T. Fletcher, and H. Yang, xe2x80x9cFungi Isolated from Tobacco Leaves and Brown-Spot Lesions Before and After Flue-Curing.xe2x80x9d Applied Microbiology, September, 1968; 16: 1309-1313; Hamilton, P. B., G. B. Lucas and R. E. Welty, xe2x80x9cMouse Toxicity of Fungi of Tobacco.xe2x80x9d Applied Microbiology, October, 1968; 18: 570-574.; and Welty, R. E. and G. B. Lucas, xe2x80x9cFungi Isolated from Flue-Cured Tobacco at Time of Sale and After Storage.xe2x80x9d Applied Microbiology, March, 1969; 17: 360-365. However, the significance and potential health hazard of aflatoxins were not considered by the tobacco industry until now. In a 1997 United States Patent to Subbiah, entitled xe2x80x9cMethod of Inhibiting Mycotoxin Production,xe2x80x9d U.S. Pat. No. 5,698,599, and assigned on its face to the R. J. Reynolds Tobacco Company, a method is disclosed for inhibiting mycotoxin production in tobacco.
Mycotoxins in general, and aflatoxins in particular, are monitored and controlled in agricultural feed and foodstuffs to minimize their impact. Current Food and Drug Administration (FDA) regulations ban use of aflatoxin-contaminated corn and grain when aflatoxin levels exceed 20 parts per billion (ppb). Similar regulations apply for other mycotoxins. Yet, due to lack of FDA authority, no regulations presently exist to mandate permissible levels of these toxins on tobacco products, both for chewing and smoking. Presently there is no regulatory oversight to ensure that tobacco and tobacco products consumed by the public are adequately screened and treated for mycotoxins, such as aflatoxins, and benzpyrene. Furthermore, there is no publicly available information which reveals that adequate measures are being taken by the tobacco industry to monitor, treat and remove these potent toxins from tobacco and tobacco products.
Treatment of tobacco to reduce such harmful toxins is of critical importance. Monitoring the production process to ensure continuous diminution is of equal importance. A failure to adequately monitor, treat and remove these harmful toxins could result in their continued presence in tobacco and tobacco products with attendant negative public health consequences.
Prior art tobacco treatment processes do not fully acknowledge or address the implications of mycotoxins (such as aflatoxins) on tobacco leaves, and therefore, the prior art processes do not adequately monitor or treat the toxins. Reformulation and reconstitution processes currently used in cigarette manufacturing appear to mimic many of the known processes for removing mycotoxins, especially aflatoxins, from agricultural products. U.S. Pat. No. 5,082,679 to Chapman, entitled xe2x80x9cMethod for Detoxifying Foodstuffsxe2x80x9d; U.S. Pat. No. 4,962,774 to Thomasson et al., entitled xe2x80x9cTobacco Reconstitution Processxe2x80x9d; U.S. Pat. No. 4,531,529 to White et al., entitled xe2x80x9cProcess for Increasing Filling Capacity of Tobaccoxe2x80x9d; and U.S. Pat. No. 4,055,674 to Yano et al., entitled xe2x80x9cMethod for the Removal of Aflatoxin from Cereals, Oil Seeds and Feedstuffs.xe2x80x9d However, these processes do not disclose continuously assaying and treating in-process tobacco to ensure adequate removal and continuous diminution of harmful toxins, such as mycotoxins and benzpyrene, from tobacco and tobacco end products.
It is therefore a general object of the invention to provide a novel process and system, which will minimize a potent toxin in tobacco, a toxin with negative public-health consequences.
It is another general object of the invention to provide a novel process and system that inhibits production of and greatly reduces levels of harmful toxins in tobacco products.
It is another general object of the invention to provide a novel process and system for continuous analysis and treatment of harmful toxins during processing of tobacco products.
It is another general object of the invention to provide a novel process and system for continuous monitoring of a wide array of harmful toxins during processing of tobacco to detect and eliminate in-process product having unacceptably high levels of toxins.
It is another general object of the invention to provide a novel process and system, which can be utilized for a wide range of tobacco products with respect to which microbial toxin detection and removal is desirable or necessary.
It is a specific object of the invention to provide for continuous assay and analysis and removal of harmful toxins, such as mycotoxins and benzpyrene, from tobacco during processing for human and animal consumption and use.
It is another specific object of the invention to provide a novel process and system for continuous assay and analysis and removal of harmful toxins from solvent and gaseous extraction streams and other processing steps.
It is another specific object of the invention to provide a novel process and system for treating tobacco prior to processing to inhibit production of harmful toxins and to monitor and ensure the absence of harmful levels of the toxins in final end products.
It is another specific object of the invention to provide a novel process and system for removing harmful toxins from tobacco processing solvent or gaseous effluent streams so that the toxin-free solvents or gases are safe for reuse or disposal.
It is another specific object of the invention to provide a novel process and system for making tobacco inert with respect to production and reformation of harmful toxins.
Preferred embodiments of the invention that are intended to accomplish at least some of the foregoing objects comprise a process and system for storage, handling, and processing of tobacco in a cigarette manufacturing facility. Production of harmful toxins is inhibited, and harmfully toxins that are present are continuously monitored, detected, and eliminated. The invention provides a process and system for continuous assayed and treatment of toxins in an in-process product by contacting the product with a solvent. The solvent is extracted and assayed for toxin content. The in-process product is again contacted with a solvent if the assayed toxin content exceeds a predetermined level of toxin. The solvent contacting, extracting and assaying steps are repeated until the assayed toxin content does not exceed a predetermined level of harmful toxin.
In one preferred embodiment of the invention, the in-process product is intended for human and animal consumption and use, such as tobacco. The toxin is a mycotoxin, and in particular an aflatoxin, or benzpyrene and its precursors. The process and system further comprises remediating the extracted solvent to remove harmful toxin and reusing the remediated solvent. Advantageously, the assaying is done by chromatography, including high-pressure liquid chromatography (HPLC), reversed-phase liquid chromatography, thin-layer chromatography, adsorption chromatography, immunoaffinity chromatography, gas chromatography; enzyme-linked immunoadsorbent assay (ELISA), fluorescent immunoassay, radioimmunoassay; spectroscopy, including mass spectroscopy, infrared spectroscopy, raman spectroscopy, packed-cell fluorescent spectroscopy; polymerase chain reaction (PCR), electron-capture decay (ECD), supercritical fluid extraction, bio-luminescence, chemical luminescence, and combinations thereof. Fluorescent immunoassay is a presently preferred best mode for assaying for aflatoxin on tobacco.
The process and system provides for monitoring toxin content to less than 300 parts per billion (ppb), in particular, less than 20 parts per billion (ppb), and more particularly, less than 0.5 parts per billion (ppb). The process and system also provides for treating in-process product to inhibit production and reformation of toxin. Advantageously, in-process product is treated prior to processing with irradiation to sterilize the product; with an inert gas environment; or with non-toxigenic fungal spores to inhibit toxin production.
In another embodiment, the process includes heating in-process product, and collecting and analyzing vapors emitted from the heated product to determine toxin content in the product. Product that has toxin content greater than 300 parts per billion (ppb) is separated from product that has toxin content less than 300 parts per billion (ppb) to eliminate grossly contaminated product.
The process and system provides for detecting toxin contamination in an in-process product and separating contaminated product. Conveving means is used for conveying in-process product to means for retaining in-process product for illumination by ultraviolet light. Detector means detects fluorescence emitted from in-process product illuminated by the ultraviolet light indicative of toxin content. Preferably, computer means may be used for controlling the retaining means to retain product for further processing when no fluorescence is detected and to discharge product when fluorescence indicative of toxin is detected.